Showing papers on "Atom interferometer published in 1994"
Book•
01 Oct 1994
TL;DR: The search for gravitational waves the nature of gravitational waves sources of gravitational wave linear systems, signals and noise optical readout noise folded interferometer arms thermal noise seismic noise and vibration isolation design of large interferometers null instruments feedback control systems an interferer as an active null instrument resonant mass gravitational wave detectors detecting gravitational wave signals gravitational wave astronomy prospects
Abstract: The search for gravitational waves the nature of gravitational waves sources of gravitational waves linear systems, signals and noise optical readout noise folded interferometer arms thermal noise seismic noise and vibration isolation design of large interferometers null instruments feedback control systems an interferometer as an active null instrument resonant mass gravitational wave detectors detecting gravitational wave signals gravitational wave astronomy prospects
522 citations
TL;DR: In this article, the recoil of an atom due to the absorption of up to 64 photons is measured, using laser-cooled cesium atoms which are made to interfere in an atomic fountain.
Abstract: The recoil of an atom due to the absorption of up to 64 photons is measured, using laser-cooled cesium atoms which are made to interfere in an atomic fountain. Measurement of the photon recoil allows a determination of ℏ/m
Cs, and hence the fine-structure constant. The measurement is described and a detailed theoretical and experimental study of potential systematic errors is presented. A relative precision in the photon recoil measurement of 0.1 ppm is obtained in two hours of data collection. The measurement is currently 0.85 ppm below the accepted value of ℏ/m
Cs. We cannot now formally ascribe a systematic error, but suspect that the bulk of the discrepancy is due to imperfections of the interferometer beams used to induce the Raman transitions.
157 citations
TL;DR: A dc hot thermal and an ac-modulated cold slow potassium beam copropagate and pass through an atom de Broglie\char21{}wave interferometer, consisting of a sequence of three microfabricated diffraction gratings, resulting in diffraction-limited shadow Moir fringes.
Abstract: A dc hot thermal and an ac-modulated cold slow potassium beam copropagate and pass through an atom de Broglie--wave interferometer, consisting of a sequence of three microfabricated diffraction gratings. Talbot-vonLau interference fringes are formed and sensed by measuring transmission with a hot wire as a function of grating position. The hot beam produces diffraction-limited shadow Moir\'e fringes, while the longer de Broglie wavelength slow beam produces interference fringes with high visibility at the fifth and sixth spatial harmonics of the shadow Moir\'e fringes.
142 citations
62 citations
29 Aug 1994
TL;DR: In this article, a calcium atomic beam using four traveling laser fields represents two distinct atom interferometers utilizing the internal degrees of freedom of the atoms, and phase shifts between the atomic partial waves have been realized by phase shifts of the laser wave fields, by the ac-Stark shift, and by rotation of the interferometer (Sagnac effect).
Abstract: Separated field excitation of a calcium atomic beam using four traveling laser fields represents two distinct atom interferometers utilizing the internal degrees of freedom of the atoms. Phase shifts between the atomic partial waves have been realized by phase shifts of the laser wave fields, by the ac-Stark shift, and by rotation of the interferometer (Sagnac effect). One particular interferometer can be selected by interaction of the atomic waves with extra laser fields. We furthermore report on the preparation of a laser cooled and deflected calcium atomic beam that can be utilized to largely increase the sensitivity of the interferometer.
33 citations
TL;DR: In this paper, the influence of acceleration, rotation, and curvature on the Ramsey interferometer and the atomic fountain was investigated. But the two-level model is appropriate for the description of atom and the perturbation can be neglected in the la-er zone.
Abstract: We ,tudy in a general treaimeni the influence oi a cla,, of perturbation~ acting on the atom, ot an atomic interferometer. An exact expre,,ion for the re,ulting ;hift of the interference pattern I, given for an arbitrary number of la;er zone; with travelling or ~tanding wave~. The a;;umption made i~ that the two-level model is appropriate for the description of atom~ and that the perturbation~ can be neglected in the la~er zone~. As an important application we calculate the influence of acceleration, rotation, and ~pace-time curvature on the Ramsey interferometer and the atomic fountain. The me»urability of the re~pective pha~e ~hift~ i~ di~cu~sed.
30 citations
TL;DR: In this article, the authors compare broadband interferometer data with narrowband bar data and show that searches for a stochastic background of gravitational wave signals can be more efficiently performed between a bar and an interferer than between two interferometers.
Abstract: Gravitational wave coincidence experiments between bars and interferometers may be an attractive option once the new generation of full scale interferometers begins taking data. We discuss various ways in which these disparate types of data can be compared in searches for bursts (from supernovae, for example), for pulsar signals, and for a stochastic background. Comparison of broadband interferometer data with narrowband bar data is appropriate in most searches for bursts, but in many cases the results---especially null results (upper limits)---are difficult to interpret. By narrowbanding the interferometer data to the bandwidth of the bar detector, one produces data sets that may give much clearer information in certain burst searches and that are appropriate for searches for a stochastic background of gravitational waves. We suggest, in fact, that there are circumstances where searches for a stochastic background could be more efficiently performed between a bar and an interferometer than between two interferometers. We examine, in some detail, the effect of narrowbanding the interferometer data. We apply this method to a real interferometer and bar data and assess its signal-to-noise performance for different classes of gravitational wave signals.
30 citations
TL;DR: In this paper, a two-level spin 1/2 atom interacting with laser fields in a gravitational background is considered. And a possible application to gravitational wave detection is outlined. But the application of spin-gravitation effects is not discussed.
Abstract: We give covariant equations for a two-level spin 1/2 atom interacting with laser fields in a gravitational background. Some gravitational effects of interest for atomic interferometry are derived, including spin-gravitation effects. A possible application to gravitational wave detection is outlined.
27 citations
TL;DR: Wave interference fringes are revealed by their selective destruction and ac-modulated laser light passes through the interferometer, is scattered by atoms at one velocity, and destroys, and thereby reveals via the ac modulation, the associated high-frequency fringe contribution.
Abstract: Atom de Broglie--wave interference fringes are revealed by their selective destruction. A thermal potassium beam is transmitted through a Talbot-Lau atom interferometer. Different fringe Fourier components resonate in the interferometer at different atomic velocities. The thermal velocity distribution averages and washes out the high-frequency components. ac-modulated laser light passes through the interferometer, is scattered by atoms at one velocity, and destroys, and thereby reveals via the ac modulation, the associated high-frequency fringe contribution.
26 citations
TL;DR: The influence of angular mirror- Orientation errors on the length of a Fabry-Perot resonator is analyzed geometrically and a simple prediction of the spectrum of short-term cavity length fluctuations resulting from mirror-orientation noise is made.
Abstract: The influence of angular mirror-orientation errors on the length of a Fabry-Perot resonator is analyzed geometrically. Under conditions in which dominant errors are static or vary slowly over time, the analysis permits a simple prediction of the spectrum of short-term cavity length fluctuations resulting from mirror-orientation noise. The resulting model is applicable to the design of mirror control systems for the Laser Interferometer Gravitational-Wave Observatory, which will monitor separations between mirrored surfaces of suspended inertial test bodies as a way to measure astrophysical gravitational radiation. The analysis is verified by measuring the response of the Laser Interferometer Gravitational- Wave Observatory's 40-m interferometer test-bed to the rotation of its mirrors.
25 citations
TL;DR: In this article, a separated beam atom interferometer was used to investigate magnetically-induced phase shifts of the different magnetic substates of the ground state of the sodium ground state.
Abstract: We have used a separated beam atom interferometer to investigate magnetically-induced phase shifts of the different magnetic substates of the sodium ground state. We have observed periodic rephasing of the 8 independent magnetic substates present in an unpolarized sodium beam as the differential magnetic field is increased on opposite sides of the interferometer. We have also demonstrated that two phase shifts with similar velocity dependences can be used to cancel each other, creating an interference pattern from one magnetic substate although an unpolarized beam is sent into the interferometer. Finally we discuss some applications of these techniques.
Journal Article•
TL;DR: In this paper, a new domain in quantum optics has emerged in recent years, namely quantum interferometry, which has been used in many applications in fundamental physics, such as light cooling and trapping experiments.
Abstract: Two new domains in quantum optics have emerged in recent years. Manipulation of atomic systems by electromagnetic fields has been developed in refined light cooling and trapping experiments. The atomic external degrees of freedom can now be controlled with great precision, and atoms can be cooled down to low temperatures corresponding to very large de Broglie wavelengths, making atomic interferometry practical and opening the way to many applications in fundamental Physics. 40 refs., 14 figs.
01 Jan 1994
TL;DR: In this article, the displacement noise spectral density of the LIGO 40 meter interferometer was monitored as samples of carbon dioxide, nitrogen, and xenon gases were admitted to its vacuum system.
Abstract: Statistical fluctuations in the column density of residual gas in the beams of a laser interferometer gravitational wave detector induce noise in the measured optical path. Resulting limits on the permissible gas pressure for a given strain sensitivity strongly influence the LIGO vacuum system’s configuration and cost. Until recently these limits were based entirely on a theoretical model. The displacement noise spectral density of the LIGO 40 meter interferometer was monitored as samples of carbon dioxide, nitrogen, and xenon gases were admitted to its vacuum system. Measurements confirm the model’s predicted dependencies on frequency, molecular polarizability and mass, and pressure. Independent calibration of the interferometer verifies that the model also accurately predicts the effect’s observed magnitude, within the 10% calibration accuracy.
TL;DR: In this article, the authors demonstrate a new technique for the mechanical manipulation of atoms with light that may be used to deflect or split an atomic beam, which depends on the existence of an internal superposition state of the atom that is "dark" to resonant excitation by a particular light field.
Abstract: We demonstrate a new technique for the mechanical manipulation of atoms with light that may be used to deflect or split an atomic beam. This technique depends on the existence of an internal superposition state of the atom that is 'dark' to resonant excitation by a particular light field. An atom in a dark state may adiabatically follow a slowly varying light field in such a way that both the internal state and the atom's momentum are changed. Because the dark state never absorbs or fluoresces, the atomic coherence, necessary for atom interferometry, is preserved. We use laser-cooled Cs atoms to demonstrate the transfer of 8 photon momenta from the slowly varying laser field to the atom.
TL;DR: Two different research teams have taken a big step toward atom interferometry by splitting atomic beams by using atoms in spin states that neither absorb nor reemit laser light.
Abstract: Two different research teams have taken a big step toward atom interferometry. They have succeeded in splitting atomic beams by using atoms in spin states that neither absorb nor reemit laser light. By proper adjustment of experimental conditions, atoms are changed from one spin state to another, without passing through the intermediary excited state. The atoms in essence absorb momentum from the laser photons, without absorption or emission of photons. The change in momentum deflects atoms in the proper spin state.
Proceedings Article•
08 May 1994TL;DR: In this article, three 0.2-μm period diffraction gratings were used to realize an interferometer for atoms and molecules that passes the interfering components of the deBroglie wave on opposite sides of a stretched metal foil positioned between two side plates.
Abstract: Three 0.2-μm period diffraction gratings were used to realize an interferometer for atoms and molecules1 that passes the interfering components of the deBroglie wave on opposite sides of a stretched metal foil positioned between two side plates. The foil was 10 cm long and 10 μ.m. thick, and a gas sample of density −2 × 1012 atoms/ cm3 could be introduced on one side of the foil only.
Book•
01 Oct 1994
TL;DR: In this paper, Schawlow et al. present a history of laser spectroscopy FIR - UV: Experimental techniques for high-resolution laser Spectroscopy of small molecules and clusters (W.M. Evenson).
Abstract: Perspectives on laser spectroscopy (A.L. Schawlow). Part 1 Laser Spectroscopy FIR - UV: Experimental techniques for high-resolution laser spectroscopy of small molecules and clusters (W. Demtroder et al.). High-resolution and high-sensitivity spectroscopy using semiconductor diode lasers (M. Inguscio). Application of laser spectroscopy to fundamental molecular species: H3+ and solid H2 (T. Oka). A history of laser frequency measurements (1967-1983) - the final measurement of the speed of light and the redefinition of the meter (K.M. Evenson). Laser spectroscopy in the far-ultraviolet region (B.P. Stoicheff). Part 2 Spectroscopy and Surface Effects: Surface spectroscopy by nonlinear optics (Y.R. Shen). Gas manipulation by light (L. Moi). Ultrahigh Resolution. High-resolution laser spectroscopy (V.P. Chebotayev). Frequency-stabilised lasers - a driving force for new spectroscopies (J.L. Hall). Part 3 Fundamental Experiments: Measurement of parity nonconservation in atoms (C.E. Wieman et al.). High-resolution spectroscopy of the hydrogen atom measurement of the Rydberg constant (L. Julien et al.) Laser spectroscopy of atomic hydrogen (T.W. Hansch). Precision atom interferometry and an improved measurement of the 13SI-23SI, transition in positronium (S. Chu). Part 4 Ion Traps: Laser stabilization to a single ion (J.C. Bergquist, W.M. Itano, D.J. Wineland). Single-atom experiments and the test of quantum physics (H. Walther). Single ions for metrology and quantum optics (P.E. Toschek). Precision hyperfine spectroscopy in ion traps (G. Werth). Part 5 Cooling: Laser cooling from the semi-classical to the quantum regime (J. Dalibard, Y. Castin). Part 6 Atom Interferometers: Atom optics (M. Sigel, C.S. Adams, J. Mlynek). Part 7 Quantum Optics: Cavity quantum electrodynamics (S. Haroche). Squeezed states of light (E. Giacobino). Part 8 Chaos: Quantum chaos and laser spectroscopy (D. Kleppner).
01 Aug 1994
TL;DR: In this article, conditions for trapping sodium atoms in far detuned dipole traps with the goal of maximizing phase space density and coherence times were explored, and a blue detuned trap was able to achieve densities as high as 2'×1012'atoms/cm3 at temperatures on the order of (11'k)2/2M.
Abstract: Conditions for trapping sodium atoms in far detuned dipole traps are explored with the goal of maximizing phase space density and coherence times. With red detuned traps, we have been able to achieve densities as high as 2 ×1012 atoms/cm3 at temperatures on the order of (11ħk)2/2M. We also report Raman cooling in a red de‐tuned trap to a one dimensional “temperature” of 0.7(ħk)2/2M. With a blue detuned trap, we have been able to observe Ramsey interference fringes between the ground states of sodium for over 4 seconds. Finally, we report an atom interferometer based on adiabatic transfer of ground state populations.
TL;DR: In this article, it was shown that oscillation or precession phenomena of atom multipole moments occur when atoms with spin S>or=1 are passing through the area occupied by a constant electric field and the presence of media located in the electric field leads to an additional phase shift of the atom wavefunction.
Abstract: It is shown that oscillation or precession phenomena of atom multipole moments occur when atoms with spin S>or=1 are passing through the area occupied by a constant electric field. The presence of media located in the electric field leads to an additional phase shift of the atom wavefunction. This effect can be used for the creation of an atomic spin interferometer and the verification of the weak equivalence principle.
TL;DR: Optical Ramsey fringes have been observed in a configuration where the atomic wave function evolves in three different internal states and only the interferometer leading to the high-frequency recoil component can be formed.
TL;DR: In this paper, the laser interferometer for the gravitational wave antenna is reviewed and the technical barriers having to be overcome in order to realize its use for gravitational wave observation are discussed.
Abstract: The laser interferometer for the gravitational wave antenna---its present status and future plan---is reviewed. A typical km class interferometer is reviewed and the technical barriers having to be overcome in order to realize its use for gravitational wave observation are discussed.
01 Jan 1994
TL;DR: In this paper, the authors report progress towards the development of a cold atom matter-wave interferometer with spatially separated beams for conducting fundamental physics experiments and for detecting gravity fields.
Abstract: Matter-wave interferometers based on beams of ultra-slow laser-cooled atoms are potentially highly sensitive inertial sensors of accelerations, rotations and fields, including gravitational fields. We report on progress towards the development of a cold atom matter-wave interferometer with spatially separated beams for conducting fundamental physics experiments and for detecting gravity fields.
01 Jan 1994
Proceedings Article•
08 May 1994TL;DR: In this paper, the interaction between a magnetic field and two standing wave laser fields can provide such a beamsplitter, but the required magnetic fields are undesirable in many interferometer applications, and few atomic systems have a suitable transition.
Abstract: Many atom interferometer applications would benefit from large angle atomic beamsplitters with narrow distributions. The interaction between a magnetic field and two standing wave laser fields can provide such a beamsplitter.1 Unfortunately, the required magnetic fields are undesirable in many interferometer applications, and few atomic systems have a suitable transition.
01 Jan 1994
TL;DR: In this article, the authors used light forces to slow, deflect, compress, cool and trap atoms; thus creating either nearly monochromatic atomic beams or atom clouds almost at rest, both of high densities and with de Broglie wavelengths up to several hundred nanometers.
Abstract: Laser manipulation of atoms has proven to be a valuable tool for preparing atomic samples for atom interferometry. Spontaneous light forces may be used to slow, deflect, compress, cool and trap atoms; thus creating either nearly monochromatic atomic beams or atom clouds almost at rest, both of high densities and with de Broglie wavelengths up to several hundred nanometers. These ensembles show sufficient spatial and temporal coherence to exhibit matter wave interference and diffraction.
01 Jan 1994
TL;DR: In this article, it has been demonstrated that the quantum mechanical wave function of an atom behaves exactly as predicted by quantum mechanics, and the experiments have been carried out at a long de Broglie wavelength range, allowing the observation of interference fringes in various types of interferometers.
Abstract: The quantum mechanical observation problems have had hypothesis which could not be observed directly until recent progress in laser technology brought such problems in the light of experimental reality in various cases. Atom interferometry is one of such examples1. By the use of recently developed laser cooling and trapping techniques, such experiments have been carried out at a long de Broglie wavelength range, allowing the observation of interference fringes in various types of interferometer. Thus it has been demonstrated beautifully that the quantum mechanical wave function of an atom behaves exactly as predicted by quantum mechanics1–5.